made me think of After Hours

that's one of the cool things about Mad Men : you never know if something has a great plot significance or is a symbol or a singal moment

Very well could be. What's the meaning of Di?
I like not trying to read into Mad Men and let the deeper layers naturally effect subconsciously and emotionally the enjoyment of the show but I'm glad there's a place for people to take it apart .

Though thinking again it sounds corny : Don finds out she's his sister and jumps off the building. BUT having the allusion to Whoring makes sense to this context. Oh well. I really like the episode, felt like a dream.

Am I the only one who assumed at first that the waitress was a lost relative of Don's? They seemed very similar to me, and it can explain the familiarity

i thought she looks like Don, is realted to him

I assumed at first that the waitress and Don were related, they do look similar.